PX4-Autopilot/src/modules/replay/replay.hpp

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#pragma once

#include <fstream>
#include <map>
#include <vector>
#include <set>
#include <string>

#include "definitions.hpp"

#include <uORB/uORBTopics.h>
#include <uORB/topics/ekf2_replay.h>

namespace px4
{

/**
 * @class Replay
 * Parses an ULog file and replays it in 'real-time'. The timestamp of each replayed message is offset
 * to match the starting time of replay. It keeps a stream for each subscription to find the next message
 * to replay. This is necessary because data messages from different subscriptions don't need to be in
 * monotonic increasing order.
 */
class Replay
{
public:
	Replay();

	/// Destructor, also waits for task exit
	virtual ~Replay();

	/**
	 * Start task.
	 * @param quiet silently fail if no log file found
	 * @param apply_params_only if true, only apply parameters from definitions section of the file
	 *                          and user-overridden parameters, then exit w/o replaying.
	 * @return OK on success.
	 */
	static int		start(bool quiet, bool apply_params_only);

	static void	task_main_trampoline(int argc, char *argv[]);

	void		task_main();

	/**
	 * Tell the replay module that we want to use replay mode.
	 * After that, only 'replay start' must be executed (typically the last step after startup).
	 * @param file_name file name of the used log replay file. Will be copied.
	 */
	static void setupReplayFile(const char *file_name);

	static bool isSetup() { return _replay_file; }

protected:

	struct Subscription {

		const orb_metadata *orb_meta = nullptr; ///< if nullptr, this subscription is invalid
		orb_advert_t orb_advert = nullptr;
		uint8_t multi_id;
		int timestamp_offset; ///< marks the field of the timestamp

		std::streampos next_read_pos;
		uint64_t next_timestamp; ///< timestamp of the file
	};

	/**
	 * publish an orb topic
	 * @param sub
	 * @param data
	 * @return true if published, false otherwise
	 */
	bool publishTopic(Subscription &sub, void *data);

	/**
	 * called when entering the main replay loop
	 */
	virtual void onEnterMainLoop() {};
	/**
	 * called when exiting the main replay loop
	 */
	virtual void onExitMainLoop() {};

	/**
	 * handle delay until topic can be published.
	 * @param next_file_timestamp timestamp of next message to publish
	 * @param timestamp_offset offset between file start time and replay start time
	 * @return timestamp that the message to publish should have
	 */
	virtual uint64_t handleTopicDelay(uint64_t next_file_time, uint64_t timestamp_offset);

	/**
	 * handle the publication of a topic update
	 * @return true if published, false otherwise
	 */
	virtual bool handleTopicUpdate(Subscription &sub, void *data);

private:
	bool _task_should_exit = false;
	std::set<std::string> _overridden_params;
	std::map<std::string, std::string> _file_formats; ///< all formats we read from the file

	uint64_t _file_start_time;
	uint64_t _replay_start_time;
	std::streampos _data_section_start; ///< first ADD_LOGGED_MSG message
	std::vector<uint8_t> _read_buffer;

	std::vector<Subscription> _subscriptions;

	/** keep track of file position to avoid adding a subscription multiple times. */
	std::streampos _subscription_file_pos = 0;

	bool readFileHeader(std::ifstream &file);

	/**
	 * Read definitions section: check formats, apply parameters and store
	 * the start of the data section.
	 * @return true on success
	 */
	bool readFileDefinitions(std::ifstream &file);

	///file parsing methods. They return false, when further parsing should be aborted.
	bool readFormat(std::ifstream &file, uint16_t msg_size);
	bool readAndAddSubscription(std::ifstream &file, uint16_t msg_size);

	/**
	 * Read the file header and definitions sections. Apply the parameters from this section
	 * and apply user-defined overridden parameters.
	 * @return true on success
	 */
	bool readDefinitionsAndApplyParams(std::ifstream &file);

	/**
	 * Read and handle additional messages starting at current file position, while position < end_position.
	 * This handles dropout and parameter update messages.
	 * We need to handle these separately, because they have no timestamp. We look at the file position instead.
	 * @return false on file error
	 */
	bool readAndHandleAdditionalMessages(std::ifstream &file, std::streampos end_position);
	bool readDropout(std::ifstream &file, uint16_t msg_size);
	bool readAndApplyParameter(std::ifstream &file, uint16_t msg_size);

	/**
	 * Find next data message for this subscription, starting with the stored file offset.
	 * Skip the first message, and if found, read the timestamp and store the new file offset.
	 * This also takes care of new subscriptions and parameter updates. When reaching EOF,
	 * the subscription is set to invalid.
	 * File seek position is arbitrary after this call.
	 * @return false on file error
	 */
	bool nextDataMessage(std::ifstream &file, Subscription &subscription, int msg_id);

	static const orb_metadata *findTopic(const std::string &name);
	/** get the array size from a type. eg. float[3] -> return float */
	static std::string extractArraySize(const std::string &type_name_full, int &array_size);
	/** get the size of a type that is not an array */
	static size_t sizeOfType(const std::string &type_name);
	/** get the size of a type that can be an array */
	static size_t sizeOfFullType(const std::string &type_name_full);

	void setUserParams(const char *filename);

	static char *_replay_file;
};


/**
 * @class ReplayEkf2
 * replay specialization for Ekf2 replay
 */
class ReplayEkf2 : public Replay
{
public:
protected:

	void onEnterMainLoop() override;
	void onExitMainLoop() override;

	uint64_t handleTopicDelay(uint64_t next_file_time, uint64_t timestamp_offset) override;

private:

	/**
	 * handle ekf2 topic publication in ekf2 replay mode
	 * @param sub
	 * @param data
	 * @return true if published, false otherwise
	 */
	bool handleTopicUpdate(Subscription &sub, void *data) override;

	void publishEkf2Topics(const ekf2_replay_s &ekf2_replay);

	int _vehicle_attitude_sub = -1;
	orb_advert_t _sensors_pub = nullptr;
	orb_advert_t _gps_pub = nullptr;
	orb_advert_t _flow_pub = nullptr;
	orb_advert_t _range_pub = nullptr;
	orb_advert_t _airspeed_pub = nullptr;
	orb_advert_t _vehicle_vision_position_pub = nullptr;
	orb_advert_t _vehicle_vision_attitude_pub = nullptr;

	int _topic_counter = 0;
};

} //namespace px4